Help: I can't open simulink block library. not responding at all

I can't open simulink block library. I get the spinning wheel at my mouse but nothing happends (I have waited 30+min multiple times). Just 2 days ago everything worked perfect. I installed latest windows updates and google chrome and after that the help functionality didn't work in matlab/simulink. I tried lots of things to fix it eventually found a solution but wanted to restore matlab/simulink to defaults by reinstalling it to be sure everything was all oke again. But now the problems are worse and even reinstalling doesn't fix it.

I tried: uninstalling matlab 2015b (all tools). removing all leftover files (and also did a register scan with CC cleaner). reinstalled matlab 2015b. still not working. (tried it multiple times)

Also HELP doesn't work afther a fresh install but I managed to fix that with this command.

com.mathworks.mlwidgets.html.HtmlComponentFactory.setDefaultType('HTMLPANEL');

Also tried these commands:

restoredefaultpath
savepath
rehash toolboxcache

I don't know what else to do (I'm considering reinstalling windows just to get matlab/simulink working again I need it to finish a project).

I'm running Windows 7 64-bit (latest updates installed) and matlab 2015b-64bit.

when I press ctrl+c I get this message and the library opens after all, but I do not trust using it

Warning: An error occurred trying to load the Simulink HMI engine.  Possible reasons include pressing
Ctrl+C or running MATLAB with the -nojvm option. Close and re-open any open any Simulink models to
assure proper functioning.  For proper functioning of Simulink HMI and the Simulation Data Inspector,
the JVM is required. 
> In slxPackager/partDefHmi
  In slxPackager/registerHandler
  In slxPackager/executeLoadCallbacks
  In slprivate (line 11)
  In load_system (line 21)
  In libbrowse2 (line 21) 
Warning: An error occurred trying to load the Simulink HMI engine.  Possible reasons include pressing
Ctrl+C or running MATLAB with the -nojvm option. Close and re-open any open any Simulink models to
assure proper functioning.  For proper functioning of Simulink HMI and the Simulation Data Inspector,
the JVM is required. 
> In DAStudio.warning (line 28)
  In slxPackager/partDefHmi
  In slxPackager/registerHandler
  In slxPackager/executeLoadCallbacks
  In slprivate (line 11)
  In load_system (line 21)
  In libbrowse2 (line 21)

Does anyone know how to fix this I'm willing to try anything

Answer 1

[Shruti Sapre]

Hi Tom,

This could be a known Java 7 issue where an operating system's IPv6 configuration prevents IPv4 loopback. That fails connector startup. A common workaround is setting "java.net.preferIPv4Stack" to "true" so JVM checks IPv4 first. The setting may be applied through java.opts or _JAVA_OPTIONS.

Some relevant links to get you started:

https://cwiki.apache.org/confluence/display/MAVEN/ConnectException

http://superuser.com/questions/453298/how-to-force-java-to-use-ipv4-instead-ipv6

<http://stackoverflow.com/questions/8367226/eclipse-failed-to-initialize-monitor-thread-unable-to-establish-loopback-conne>

Hope this helps!

-Shruti

[Tom Klijn]

Hello, thank you for your answer. I already did a reinstall of windows so I can't try your solution. Everything is working correctly now.

[Franky Pan]

Thank you so much！I met this problem and I almost broke down... Your solution is right. I finally solved this problem. HAHAHAH